Rollback: Add PacketSharingOwnership, a safer replacement for PointToForeign.

PiperOrigin-RevId: 507288476

mediapipe/framework/api2/packet.h

@@ -242,8 +242,6 @@ class Packet : public Packet<internal::Generic> {
   friend Packet<U> PacketAdopting(const U* ptr);
   template <typename U>
   friend Packet<U> PacketAdopting(std::unique_ptr<U> ptr);
-  template <typename U>
-  friend Packet<U> PacketSharingOwnership(std::shared_ptr<const U> ptr);
 };
 
 namespace internal {
@@ -466,17 +464,6 @@ Packet<T> PacketAdopting(std::unique_ptr<T> ptr) {
   return Packet<T>(std::make_shared<packet_internal::Holder<T>>(ptr.release()));
 }
 
-template <typename T>
-Packet<T> PacketSharingOwnership(std::shared_ptr<const T> ptr) {
-  return Packet<T>(
-      std::make_shared<packet_internal::ForeignHolder<T>>(std::move(ptr)));
-}
-
-template <typename T>
-std::shared_ptr<const T> SharedPtrWithPacket(Packet<T> packet) {
-  return mediapipe::SharedPtrWithPacket<T>(std::move(packet));
-}
-
 }  // namespace api2
 }  // namespace mediapipe
 

mediapipe/framework/api2/packet_test.cc

@@ -162,21 +162,6 @@ TEST(PacketTest, PacketAdopting) {
   EXPECT_FALSE(p.IsEmpty());
 }
 
-TEST(PacketTest, PacketSharingOwnership) {
-  bool deleted = false;
-  std::shared_ptr<const int> object(new int(42), [&deleted](const int* p) {
-    delete p;
-    deleted = true;
-  });
-  Packet<int> p = PacketSharingOwnership(object);
-  EXPECT_FALSE(p.IsEmpty());
-  EXPECT_EQ(p.Get(), 42);
-  object = nullptr;
-  EXPECT_FALSE(deleted);  // Packet keeps it alive.
-  p = {};
-  ASSERT_TRUE(deleted);  // last owner expired.
-}
-
 TEST(PacketTest, PacketGeneric) {
   // With C++17, Packet<> could be written simply as Packet.
   Packet<> p = PacketAdopting(new float(1.0));
@@ -296,24 +281,6 @@ TEST(PacketTest, PolymorphismAbstract) {
   EXPECT_EQ(base->name(), "ConcreteDerived");
 }
 
-TEST(PacketTest, ShareSubobjectOwnership) {
-  // Create a packet that contains a vector and tracks deletion.
-  bool deleted = false;
-  std::shared_ptr<const std::vector<int>> ints(new std::vector<int>{0, 1, 2, 3},
-                                               [&deleted](std::vector<int>* p) {
-                                                 delete p;
-                                                 deleted = true;
-                                               });
-  auto vector_packet = PacketSharingOwnership(std::move(ints));
-  // Create a packet that references one of the items in the vector.
-  Packet<int> item_packet = PacketSharingOwnership(std::shared_ptr<const int>(
-      SharedPtrWithPacket(vector_packet), &vector_packet.Get()[1]));
-  vector_packet = {};
-  ASSERT_FALSE(deleted);  // item_packet keeps it alive
-  item_packet = {};
-  ASSERT_TRUE(deleted);
-}
-
 }  // namespace
 }  // namespace api2
 }  // namespace mediapipe